This invention relates to electronic circuits for converting an analogue measurement for digital readout and transmission. More particularly, it relates to providing a circuit capable of converting a scale reading of a mechanical scale into an electronic data bit stream which can be utilized for digital displays and is suitable for use by a general purpose computer.
In asphalt, cement and similar plants, mechanical scales are present on large towers which dispense the materials into trucks for dispatching to a job site. The quantity of material is determined by the mechanical scales. Such scales are difficult to read and are remote from a central plant control. Further, it is necessary to have a scale reader present to accurately record the values of materials which are loaded onto the trucks.
In order to eliminate the need for a scale reader and further, in order to provide the data in a form which can be transmitted relatively long distances and over inexpensive transmission lines in a noisy environment, a circuit for encoding the weight data is desirable. It will be apparent that there are many other applications for the circuit of the present invention as for example, truck weight stations. In fact, as will become apparent from the specification, the present invention provides an advantageous means of transmitting digitized data relating to the rotation of any mechanical device where such movement indicates useful information.
It is accordingly an object of the present invention to provide a digital shaft encoder circuit for rotational devices which can convert the mechanical rotation of the device into digital information.
It is a further object of the present invention to provide a shaft encoder circuit for digitizing signals from a mechanical scale.
It is yet another object of the present invention to provide a circuit for encoding data for transmission over relatively long distances.
Other objects and advantages of the invention will become apparent from the remaining portion of the specification.